Religion was incorporated within the empire along with may other things which is one of the reasons it was so successful for so long.
In other words it's because they were tolerant of other religions (answer B).
B) large tracts of land to citizens
Answer: A. Analyses of the behavior of seismic waves.
Explanation: "The layering of Earth has been inferred indirectly using the time of travel of refracted and reflected seismic waves created by earthquakes" (Structure of the Earth). Combining the layered structure and reflection magnitudes with the magnitude of gravity (and therefore the average density of the Earth), we can get a pretty good idea of the density of each layer. By integrating density, we can calculate the pressures at depth."
Australia......... if not the New Zealand